Sewer Cop

Keeping the filth out of the city's wastewater

Greg Yarnik, a pollution-control officer with the Metropolitan Water Reclamation District, drives to the edge of a parking lot outside the McCain Citrus juice-processing plant in Lawndale and parks before a dirty fiberglass hut. The hut houses a machine that looks like a shop vac crowned with a cluster of tubes and wires, all perched on a shelf that spans an open manhole. A computer cable connects the shop vac to a retrofitted tackle box containing a stylus-and-graph-paper monitor, and a clear plastic tube dangles from its head into the darkness below. Every so often the contraption coughs into action. The base quivers, the circuitry whirs and clicks, and the dangling straw sucks a slug of gray water into a collecting basin within the machine's body. Yarnik pours the contents of the basin into a sampling jar and notes the reading from the tackle-box monitor in a logbook.

Yarnik regularly consults shop vacs in industrial parking lots throughout Chicago and the western suburbs, making a couple hundred site visits a year. The data he collects on industrial wastewater play a big role in his mission, which he describes as "keeping the sewers free of substances having a deleterious effect on the district's treatment capabilities." He translates: "If you put something in the sewer that shouldn't be there, we find you."

If lab tests reveal illegal substances in a company's wastewater, the MWRD can take a number of actions, depending on the severity of the contamination and the company's record of compliance with the law. It might issue a warning or levy a fine for a mild infraction. It might file criminal charges in a more serious case. Companies still sneak illegal substances into sewers, most often to avoid paying for their proper disposal, but clues usually turn up somewhere. "The investigative responsibilities," Yarnik says, "are my favorite part of the job."

Those clues frequently come from organizations or individuals calling to complain about something funny in a sewer or waterway. Every call launches an MWRD inquiry. A recent "Biannual Report of Emergency Response Activities," which summarizes all the MWRD investigations from the previous six months, lists complaints ranging from "dead fish in storm water retention pond" to "green discoloration in Chicago River." Many callers detected a "noxious odor emanating from sewer." One person spied "fish in distress in North Shore Channel." Yarnik says he solves well over half of the cases he goes out on.

Sometimes the source of a problem can't be precisely determined. For over a hundred years, Yarnik explains, the river was nothing more than an open sewer. Much of what was dumped in it sank to the bottom and congealed into a toxic sludge that's now many feet thick. Environmental legislation has halted the wholesale dumping, and fish once more swim in the river. But the sludge remains. Occasionally some of it percolates up, blooming into a rainbow sheen across the river's surface. Dredging the river would only further contaminate the water. Yarnik sighs, "That sludge is never leaving--no how, no way."

But MWRD investigators, who together monitor 500 to 600 sites, can often pinpoint the source of contamination. A recent investigation targeted Silver Creek--in Yarnik's words, "a shallow, slow-moving, typical urban stream" that meanders through the western suburbs, past O'Hare airport, and into the Des Plaines River. A few years ago the MWRD started receiving complaints from area residents that the creek was giving off an uncharacteristic stench and was streaked with new, unnatural shades of green and pink. Yarnik suspected an illegal tie-in.

Illegal tie-ins tend to occur in newer communities where the sewers are separated into two systems instead of one: a storm-sewer system that handles rain and snow (relatively untainted water) and a sanitary system that accepts household and industrial waste (sewage). Drains located outside buildings generally run into the storm-sewer system, while drains located inside buildings run into the sanitary system. Two such systems drain the area along Silver Creek, and both eventually run into the creek, though they take different routes. The storm system leads directly into the waterway, while the sanitary system makes a detour through the sewage-treatment plant. An illegal tie-in happens when a company attaches its plumbing to the storm rather than the sanitary system.

To check their hunch that a business was sending its untreated sewage directly into Silver Creek, Yarnik and his supervisor, Bob Renaud, flushed a brightly colored, fluorescent liquid down the sinks, toilets, and drains of every business along the creek, then watched for Day-Glo slicks.

"We went fishing for tuna," says Renaud, "but caught quite a few minnow as well." They discovered that many businesses had drains connected to the wrong pipe, though the funny plumbing was often a subcontractor's mistake, not a corporate strategy. Most of the companies immediately corrected the problem.

The pollution Yarnik and Renaud had found consisted mainly of organic manufacturing wastes. Organic wastes--fat, oil, grease, animal or vegetable matter, feces--can stink up the water, and great quantities can turn a river septic by depleting it of oxygen. But at normal concentrations, organic wastes are easily removed from industrial effluent--as long as they go through a treatment plant.

Inorganic wastes can be scarier. The scariest, primarily heavy metals such as lead and mercury, are dangerous even in extremely small quantities. How small? The city's Sewage and Waste Control Ordinance, passed in 1994, sets the allowable concentration of barium in wastewater at no more than two parts per million. Zinc can't exceed one part per million, mercury half a part per billion. Heavy metals can't be removed from water, and they will kill the bacteria the MWRD uses to treat sewage. Even relatively low concentrations can disable an entire treatment plant. They can also be deadly to aquatic life.

On August 1, 1989, sometime between midnight and 2 AM, a supervisor at P & H Plating Company on West Belmont removed a 1,000-gallon drum of used metal-finishing solution from storage and emptied it into the sewer. Roughly 15 minutes later alarms went off throughout the MWRD's north-side sewage-treatment plant. Sensors in the sewer line had detected large concentrations of cadmium cyanide coming down the pipes--enough to knock the plant out of commission for months. The operators on duty had no choice but to close the intake valves, forcing the raw sewage to bypass the plant and run directly into the Chicago River. The next morning the North Branch was clogged with the bodies of more than 10,000 dead fish. "This was an extreme case," says Yarnik, "the worst pass-through event in my memory."

MWRD investigators knew the dumper had to be upsewer, and industry profiles told them which companies kept cadmium cyanide on hand. They eventually shrank the pool of suspects to a small group of plating companies on the northwest side. But then the investigation hit a wall. Companies that dump 1,000 gallons of poison into a river usually hide the barrel when they're done. And there was of course the possibility that the perpetrator wasn't a local business. "It could have been just some guy coming through in a truck," says Yarnik.

The MWRD offered a reward for information leading to the dumper's arrest, and a disgruntled P & H employee apparently fingered the couple who owned and operated the company. On December 4, 1991, over two years later, the pair pleaded guilty.

Back in the McCain Citrus parking lot Yarnik loads the sewage samples into his van. He and the other investigators pick up samples about 40,000 times a year. They monitor companies such as McCain, which use relatively benign chemicals, only one week out of the year, but they monitor plants that pose more of a hazard year-round. Yarnik knows they won't catch every polluter, but at least companies know someone's out there watching them.

Art accompanying story in printed newspaper (not available in this archive): Greg Yarnik photo by Cynthia Howe.